Wheat dwarf genes Rht12 and Rht‐B1b affected the performance of agronomic traits in hexaploid triticale

Abstract

As a new synthetic species, triticale has been widely used for food and feed. Lodging is a severe problem in triticale production, and it is unknown whether wheat height‐reducing genes can improve lodging resistance in triticale. In this study, the wheat‐dwarfing genes Rht12 and Rht‐B1b were introgressed into hexaploid triticale (AABBRR) lines to understand their effect on plant height. The results showed that Rht12 and Rht‐B1b reduced the plant height of triticale plants by 37.7 and 29.9%, respectively. Rht12 and Rht‐B1b both had significant effects on the basal internode's length, diameter, and thickness, which may greatly improve lodging resistance. Additionally, the net photosynthetic rate was increased by 28.7% in Rht12 dwarf lines. However, Rht12 had a significant and negative effect on thousand‐kernel weight (14.5%) and yield per plant (20.6%). On the other hand, Rht‐B1b reduced the number of tillers by 19.6% and yield per plant by 18.1% with no negative effect on the harvest index. Furthermore, Rht12 and Rht‐B1b decreased grain plumpness but improved several grain quality traits. Conclusively, Rht12 and Rht‐B1b improved lodging resistance but had some negative effects on yield components, which need careful consideration in triticale breeding.